Torque converter with clutch engaged and released by different pressures



1968 J. G. CADlOU TORQUE CONVERTER WITH CLUTCH ENGAGED AND RELEAS BYDIFFERENT PRESSURES Filed Sept. 50, 1966 3 Sheets-Sheet 1 Dec. 10, 1968J. G. CADIOU 3,415,345

TORQUE CONVERTER WITH CLUTCH ENG D AND RELEASED BY DIFFERENT P RESSU EFiled Sept. 30, 1966 3 Sheets-Sheet 2 Dec. 10, 1968 .G. CADIOU 3,415,345

TORQUE CONVERTER H CL CH ENGAGED AND RELEASED BY DIFFER PRESSURES FiledSept. 30, 1966 3 Sheets-Sheet 3 ,mmv

United States Patent 7 Claims. til. 192--s.s3

ABSTRACT OF THE DISCLOSURE A hydraulically operated torque converter anda mechanical clutch adapted to be connected to one element of theconverter. A distributor device for selectively establishing thehydraulic fluid pressure at suitable predetermined values in controlcircuits for the mechanical clutch. A first fluid circuit to feed fluidunder pressure to a first face of the clutch plate in the direction ofdeclutching and a second fluid circuit to feed fluid under pressure tothe torque converter and simultaneously to the other face of the clutchplate in the direction of clutching. The two fluid circuits each havinga discharge valve therein, and the discharge valve of the first fluidcircuit controlling the pressure in the first circuit so that thepressure therein is greater than the discharge pressure controlled bythe valve of the second fluid circuit.

In certain motor vehicles, a power transmission is used whichessentially comprises a hyd-rokinetic torque converter associated with amechanical clutch, operating in oil, connected to the output turbine ofthe converter, for driving a conventional gear box. An axially movableplate, adjacent the mechanical clutch, causes the latter to be engagedor put into the rest position. To this end, this plate is exposed on oneor other of its faces to oil under pressure which can pass through theconverter. The reversal of the direction of circulation of this oilcauses the pressure to exert itself on one or other of the faces of theplate and consequently produces the clutching or declutching of themechanical component. The desired reversal is effected by vmeans of adistributor connected for example to the gear change lever under theoperation of the driver.

It will be apparent that the declutching action must be rapid. Thisresult is most surely obtained by giving the fluid a high pressure whichmost easily supports the charge losses of the circuit and which mostclearly rises above the opposing dynamic pressure which becomesconsiderable at high speeds of rotation.

On the other hand, it is not desirable that the converter shall operateat too high an oil pressure which is added to the dynamic pressure andwhich subjects it to stresses which are too high.

Attempts have previously been made to reconcile these two opposingdesiderata, by choosing an oil pressure of intermediate 'value which isa disadvantage for the operation of the mechanical clutch and theconverter.

The invention has for an object satisfying these two desiderata of lowpressure and high pressure, in order to obtain, in all circumstances,the best operation of the components incorporated.

To this end, according to the invention, the oil circuit senving toapply oil under pressure on the face of the plate in the direction ofdeclutching is provided with an adjustable discharge valve whilst thecircuit serving to apply oil under pressure on the other face of theplate in the direction of clutching is provided with another adjustabledischarge valve which is adjusted to a value which is different from theadjustment of the first valve.

3,415,345 Patented Dec. 10, 1968 In a preferred embodiment of theinvention, the adjusted valve for the lower pressure is situated on thebody of the distributor substantially in the same transverse plane asthe outlet aperture of the corresponding direction of distribution,whilst the valve adjusted to the higher pressure is situated on the bodyof the distributor, in the same discharge chamber as the precedingvalve, substantially in the same transverse: plane as the inlet apertureof the oil in the distributor.

In order that the invention may be more readily understood and itssecondary features as well as its advantages may be more readilyappreciated, reference will now be made to the accompanying drawingswhich show certain embodiments thereof by way of example, and in which:

FIGURE 1 shows schematic sectional view of a mechanical clutch-converterassembly with two directions of oil circulation,

FIGURE 2 shows a sectional view of a distributor according to theinvention, associated with the assembly of FIGURE 1, and shown in afirst position,

FIGURE 3 shows a sectional view similar to FIGURE 2, but the distributorbeing shown in its second position,

FIGURE 4 shows a part-schematic View showing a modification of theadjustable valves in the distribution circuit,

FIGURE 5 shows a part-schematic view showing an other modification ofthe adjustable valves, and

FIGURE 6 shows a general schematic view showing the circuit forconnecting the distributor of FIGURES 2 and 3 to the clutch-converterassembly.

Refer-ring now to the drawings, FIGURE 1 shows a converter generallyindicated at 1, and having an output turbine 2 connected to a mechanicalclutch generally designated at 3. This latter may be engaged with theaid of a plate 4 mounted to slide on a hollow shaft 5 which is itselflocated inside another hollow shaft 6. Since such an assembly is alreadyknown, it does not appear necessary to describe it in detail. It issufiicient to note here that the hollow concentric shafts 5 and 6constitute an oil inlet circuit in which the circulation may be effectedin the direction of arrows F (in solid lines) or in the direction ofarrows F (in interrupted lines).

In the first case, the oil under pressure bears upon the face 4a (on theleft of the figure) of the plate 4, engages the clutch 3, and passesthrough the converter 1.

In the second case, the oil under pressure bears on the opposite face41) of the plate 4 and produces the declutching of the mechanicalclutch.

The reversal of the direction of circulation is effected by means of adistributor which is shown in FIGURES 2 and 3. It comprises acylindrical body 7 containing a distribution slide or piston 8 which canbe moved between two positions under the effect of an external action,exerted in the direction F by means of a thrust member 9 against theaction of a return spring 10 situated at the opposite end between theslide 8 and the body 7.

This latter has a central lateral aperture 11 connected to a pump 18 forsupplying pressurised fluid (shown in FIGURE 6) and two end apertures 12and 13 connected respectively, one to the hollow shaft 5 (direction ofcirculation F) the other to the hollow shaft 6 (direction of circulationF).

Along the body 7, opposite the apertures 11, 12 and 13, there is adischarge chamber 114 with which the extreme volumes existing bet-weenthe slide 8 and the cylindrical body 7 communicate.

This chamber 14 is itself connected by means of an aperture 15 to theoil tank of the pump 18 (FIGURE 6). In the chamber 14 there are located,parallel to one another, two biased discharge valves 16 and 17 which areadjusted to different opening values by springs 16a and 17a, arelatively low value spring 16a for valve 16, relatively high valuespring 17a for valve 17. The springs 16a and 17a may be of coursereplaced by springs having different strengths to accurately adjust theopening of the valves under all pressure conditions.

The valve 16 is situated opposite the outlet aperture 12, practically inthe same transverse plane, whilst the valve 17 is similarly situatedopposite the inlet aperture 11.

In the position of the slide 8 which can be seen in FIGURE 2, the inletaperture 11 is placed in communication with the outlet aperture 12; thetwo valves 16 and 17 are subjected to the pressure of the oil sent bythe pump. The valve 16, with a lower strength spring, opens by itself.The circulation is effected in the direction F- under a low pressure andcauses the mechanical clutch 3 to come into operation.

In the second position of the slide 8 which can be seen in FIGURE 3, theinlet aperture 11 is placed in communication with the outlet aperture13; the valve 16 is isolated but the valve 17 remains exposed to thepressure and it regulates the value of the latter to a high level.Circulation is effected in the direction F at a high pressure whichensures a complete and rapid declutohing of the clutch 3.

Consequently, due to the invention, two different pressures are obtainedin the same circuit according to the direction of circulation of theoil. Declutching is effected more clearly whilst the converter operatesat the highest pressure which is suitable for it. The pump discharges,for most of the time, at low pressure, this being favourable to itsduration and to the silence of its operation.

It is obvious that the two valves 16 and 17 can be arranged differently;an embodiment has been described which is considered to be particularlyadvantageous but it will be apparent that either of the valves could beplaced, for example, separately on the outlet apertures 12 and 13 of thedistributor. 'llhis modification can be seen in FIGURE 4 Where thevalves 16 and 17, having low and high strength springs respectively, aremounted on the outlet pipes 12 and 13 of the distributor and areconnected by a return tube 15'.

In another modification (FIGURE 5), the valve 17" having the highstrength spring can be placed on the supply pipe 11 of the distributor.

I claim:

1. An arrangement comprising a hydraulically operable torque converterhaving a mechanical clutch connectable to one element of said converter;said mechanical clutch including a clutch plate having two oppositelydirected faces and a distributor device for actuating said plate; saiddistributor device comprising a first fluid circuit to feed fluid underpressure to a first face of said clutch plate so as to actuate the platein the direction of declutching, and a second fluid circuit to feedfluid under pressure simultaneously to the torque converter and to theother face of the clutch plate so as to actuate said plate in thedirection of clutching; and a regulated discharge valve contained ineach of said two fluid circuits; the discharge valve of the first fluidcircuit being regulated so as to cause the discharge pressure of saidfirst fluid circuit to be greater than the discharge pressure of thesecond fluid circuit to thereby allow said clutch plate to be operatedmore rapidly in the direction of declutchmg.

2. An arrangement according to claim 1, wherein said valves open into adischarge chamber incorporated in said distributor device.

3. An arrangement according to claim 1, wherein said valves are locatedin outlet apertures of said distributor device directed towards areasadjacent the said two faces of said clutch plate, said two dischargeoutlets being con nected to a return pipe.

4. An arrangement according to claim I wherein said valve regulated soas to cause the greater discharge pres sure is located at the inletaperture of asid distributor device.

5. An arrangement according to claim 1, wherein said valves are locatedin extensions of the outlet apertures of said distributor devicedirected towards areas adjacent the said two faces of said clutch plate,said two discharge outlets being connected to a return pipe.

6. An arrangement according to claim 1 wherein said valve regulated soas to cause the greater discharge pressure is located in the supplyconduit leading to the inlet aperture of said distributor device.

7. An arrangement according to claim 1 wherein the means for regulatingsaid discharge valves are different strength springs; the springregulating said valve causing the greater discharge pressure being of ahigher strength than the spring regulating the pressure of the secondfluid circuit.

References Cited UNITED STATES PATENTS 2,736,412 2/1956 LiveZey 1923.3X2,824,632 2/1958 Lucia et al. 192-33 2,992,713 7/1961 Stump et al.1923.33 3,224,537 12/1965 Hilpert 1923.3 X 3,235,043 2/1966 Maurice etal. 1923.33 X

BENJAMIN W. WYCH-E 111, Primary Examiner.

US. Cl. 19286

